elastin and Hydronephrosis

We evaluated the collagen-to-smooth muscle tissue matrix ratio and percentage of elastin in the renal pelvis, ureteropelvic junction (UPJ) and ureter, and compared these findings with the degree of obstruction, patient age and post-pyeloplasty renal recovery.. We analyzed histological sections from 75 patients with UPJ obstruction. Nine patients were excluded owing to bilateral UPJ obstruction and an improper specimen. We divided the specimen obtained from pyeloplasty into 3 parts, namely the renal pelvis above the obstruction, the obstructed UPJ portion and the ureter below the obstruction. To examine the collagen and smooth muscle, sections were stained using Masson's trichrome, and elastic van Giesson stain was used for elastin, smooth muscle and collagen. Collagen, smooth muscle and elastin populations were identified, and the tissue matrix ratio and percentage of elastin were calculated by color image analysis.. In patients with lower ratios of collagen-to-smooth muscle in the UPJ proper hydronephrosis was more improved postoperatively (p = 0.049). In patients with a lower percentage of elastin in the renal pelvis, UPJ and ureter hydronephrosis was more improved postoperatively (p <0.0001).. Because the UPJ portion was resected during pyeloplasty, the renal pelvis and the ureter remaining after pyeloplasty are likely to be related to improved hydronephrosis. A higher percentage of elastin in the renal pelvis and ureter contributes to inelasticity and low compliance, and results in a slower recovery from hydronephrosis after pyeloplasty.

Topics: Adolescent; Child; Child, Preschool; Elastin; Female; Humans; Hydronephrosis; Infant; Infant, Newborn; Kidney Pelvis; Male; Retrospective Studies; Ureter; Urologic Surgical Procedures

Topics: Animals; Body Weight; Collagen Type I; Collagen Type III; Disease Models, Animal; Elastin; Extracellular Matrix Proteins; Female; Fetal Diseases; Fibrillins; Fibronectins; Gene Expression; Hydronephrosis; Ligation; Male; Microfilament Proteins; Organ Size; Pregnancy; RNA, Messenger; Sex Factors; Sheep; Ultrasonography; Urinary Bladder; Urinary Bladder Neck Obstruction

Histological, histochemical and electron microscopic techniques have been used to compare dilated and normal calibre segments of ureter and renal pelvis in cases of idiopathic hydronephrosis and primary obstructive megaureter. In both conditions a marked increase in collagen and elastic tissue occurs in the wall of the distended segment and this infiltration extends throughout the proximal dilated ureter and renal pelvis. Evidence is presented to show that in the dilated segment, smooth muscle cells are directly involved in the synthesis of connective tissue elements. These findings support the view that the primary anomaly in idiopathic hydronephrosis and primary obstructive megaureter can be attributed to a malfunction of smooth muscle cells in the ureter and renal pelvis. However, the possibility remains that the changes in smooth muscle are secondary and have been induced by obstruction and distension caused in these pathological conditions by unknown aetiological factors.

Topics: Cholinesterases; Collagen; Connective Tissue; Dilatation, Pathologic; Elastic Tissue; Elastin; Histocytochemistry; Humans; Hydronephrosis; Kidney Pelvis; Microscopy, Electron; Muscle, Smooth; Ureter; Ureteral Obstruction